"I extend my deepest condolences to those so terribly injured in this terrorist attack and to the many killed and the families, so many families, of the victims. We stand in absolute solidarity with the people of the United Kingdom," Trump said, in his first comment on the Monday night attack at a concert Manchester, England.

While police believe the suspect was acting alone, investigations are ongoing to establish if he was part of a network.

Trump said: "So many young beautiful innocent people living and enjoying their lives murdered by evil losers in life. I won't call them monsters because they would like that term. They would think that's a great name. I will call them from now on losers because that's what they are."

President Donald Trump responds to the Manchester terror attack during a joint press conference with Palestinian Authority President Mahmoud Abbas in the West Bank city of Bethlehem on May 23, 2017.

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"They're losers, and we'll have more of them, but they're losers, just remember that," he added.

The phrase "evil losers" was Trump's own idea, a senior White House official said, adding he went over it with his team Tuesday morning at the King David Hotel in Jerusalem before delivering the speech.

Trump delivered his remarks alongside Palestinian Authority President Mahmoud Abbas in the West Bank city of Bethlehem, where the two men met to advance peace talks on the Israeli-Palestinian conflict. Abbas also expressed his "warm condolences" to the victims of the attack and to the British people.

Trump called on all countries to unite in the fight against terrorism and proclaimed: "This wicked ideology must be obliterated."

"Our society can have no tolerance for this continuation of bloodshed. We cannot stand a moment longer for the slaughter of innocent people. And in today's attack it was mostly innocent children. The terrorists and extremists and those who give them aid and comfort must be driven out from our society forever," Trump said.